Abstract
The surface profile evolution model, which was initially developed for glass and polymers, can accurately predict a channel profile cross-section produced by abrasive jet (AJ) machining. In this study, the model is modified and applied for estimating the profiles of a Ti-6Al-4V alloy eroded by an abrasive waterjet (AWJ). First, the velocity and mass fraction distributions of the gas–liquid–solid phases in the AWJ at the nozzle exit were derived and compared, and several improvements were proposed, such as considering the divergence angle of the jet and particles, as well as the length of the jet core area, to precisely construct a theoretical connection of the erosion efficiency distribution before impacting the workpiece. Computational fluid dynamics (CFD) simulations were then performed to investigate the behaviour of the erosion jets during surface evolution. The results revealed that the jet diffusion provoked by the stagnation zone effect became more pronounced as the surface profile depth deepened, which led to jet directional deflection and suppressed the erosion capacities of the AWJ. Therefore, a central erosion depth function was introduced to correct this detrimental effect with the intention of obtaining an accurate channel profile. In addition, a second-order single-step fitting function was suggested to eliminate the fluctuations caused by uneven abrasive particles and the problem of reduced erosion efficiency due to channel depth variation. Finally, based on the determination of the parameters affecting the channel profile, a normalised centre erosion rate function, which only depends on the channel depth and is isolated from the material properties and the standoff distance, was recommended to simplify the calculation. The erosion function conforming to a Gaussian surface was fitted using MATLAB (R2019b, MathWorks, USA). The results demonstrated that the channel profiles predicted by the surface evolution model were consistent with the measured profiles, with an average error of 11.4%.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
